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diff --git a/sag-0.6.1-www/Invisible/sag-0.6/node99.html b/sag-0.6.1-www/Invisible/sag-0.6/node99.html new file mode 100644 index 0000000..03c11d6 --- /dev/null +++ b/sag-0.6.1-www/Invisible/sag-0.6/node99.html @@ -0,0 +1,71 @@ +<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN"> +<!--Converted with LaTeX2HTML 96.1-h (September 30, 1996) by Nikos Drakos (nikos@cbl.leeds.ac.uk), CBLU, University of Leeds --> +<HTML> +<HEAD> +<TITLE>Selecting the backup tool</TITLE> +<META NAME="description" CONTENT="Selecting the backup tool"> +<META NAME="keywords" CONTENT="sag"> +<META NAME="resource-type" CONTENT="document"> +<META NAME="distribution" CONTENT="global"> +<LINK REL=STYLESHEET HREF="sag.css"> +</HEAD> +<BODY LANG="EN" > + <A NAME="tex2html1565" HREF="node100.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html1563" HREF="node96.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html1557" HREF="node98.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html1567" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html1568" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html1566" HREF="node100.html">Simple backups</A> +<B>Up:</B> <A NAME="tex2html1564" HREF="node96.html">Backups</A> +<B> Previous:</B> <A NAME="tex2html1558" HREF="node98.html">Selecting the backup medium</A> +<BR> <P> +<H1><A NAME="SECTION001130000000000000000">Selecting the backup tool</A></H1> +<P> + There are many tools that can be used to make backups. The + traditional UNIX tools used for backups are <tt>tar</tt><A NAME="3020"> </A>, + <tt>cpio</tt><A NAME="3022"> </A>, and <tt>dump</tt><A NAME="3024"> </A>. In addition, there are + large number of third party packages (both freeware and + commercial) that can be used. The choice of backup medium + can affect the choice of tool. +<P> + <tt>tar</tt><A NAME="3026"> </A> and <tt>cpio</tt><A NAME="3028"> </A> are similar, and mostly equivalent + from a backup point of view. Both are capable of storing + files on tapes, and retrieving files from them. Both are + capable of using almost any media, since the kernel device + drivers take care of the low level device handling and the + devices all tend to look alike to user level programs. + Some UNIX versions of <tt>tar</tt><A NAME="3030"> </A> and <tt>cpio</tt><A NAME="3032"> </A> may have + problems with unusual files (symbolic links, device files, + files with very long pathnames, and so on), but the Linux + versions should handle all files correctly. +<P> + <tt>dump</tt><A NAME="3034"> </A> is different in that it reads the filesystem + directly and not via the filesystem. It is also written + specifically for backups; <tt>tar</tt><A NAME="3036"> </A> and <tt>cpio</tt><A NAME="3038"> </A> are + really for archiving files, although they work for backups + as well. +<P> + Reading the filesystem directly has some advantages. It makes + it possible to back files up without affecting their time + stamps; for <tt>tar</tt><A NAME="3040"> </A> and <tt>cpio</tt><A NAME="3042"> </A>, you would have to mount + the filesystem read-only first. Directly reading the filesystem + is also more effective, if everything needs to be backed up, + since it can be done with much less disk head movement. The + major disadvantage is that it makes the backup program specific + to one filesystem type; the Linux <tt>dump</tt><A NAME="3044"> </A> program understands + the ext2 filesystem only. +<P> + <tt>dump</tt><A NAME="3046"> </A> also directly supports backup levels (which we'll + be discussing below); with <tt>tar</tt><A NAME="3048"> </A> and <tt>cpio</tt><A NAME="3050"> </A> this has + to be implemented with other tools. +<P> + A comparison of the third party backup tools is beyond the + scope of this book. The Linux Software Map lists many of the + freeware ones. +<P> +<HR><A NAME="tex2html1565" HREF="node100.html"><IMG WIDTH=37 HEIGHT=24 ALIGN=BOTTOM ALT="next" SRC="./next_motif.gif"></A> <A NAME="tex2html1563" HREF="node96.html"><IMG WIDTH=26 HEIGHT=24 ALIGN=BOTTOM ALT="up" SRC="./up_motif.gif"></A> <A NAME="tex2html1557" HREF="node98.html"><IMG WIDTH=63 HEIGHT=24 ALIGN=BOTTOM ALT="previous" SRC="./previous_motif.gif"></A> <A NAME="tex2html1567" HREF="node1.html"><IMG WIDTH=65 HEIGHT=24 ALIGN=BOTTOM ALT="contents" SRC="./contents_motif.gif"></A> <A NAME="tex2html1568" HREF="node114.html"><IMG WIDTH=43 HEIGHT=24 ALIGN=BOTTOM ALT="index" SRC="./index_motif.gif"></A> <BR> +<B> Next:</B> <A NAME="tex2html1566" HREF="node100.html">Simple backups</A> +<B>Up:</B> <A NAME="tex2html1564" HREF="node96.html">Backups</A> +<B> Previous:</B> <A NAME="tex2html1558" HREF="node98.html">Selecting the backup medium</A> +<P><ADDRESS> +<I>Lars Wirzenius <BR> +Sat Nov 15 02:32:11 EET 1997</I> +</ADDRESS> +</BODY> +</HTML> |